1. Field of the Invention
The invention relates to a golf club grip, more particularly to a golf club grip having a hem structure for finishing and hemming the marginal edges of a winding sheet layer.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional golf club grip 1 includes a fabric lining 11 adhered by means of a natural fixative 10 to a golf club shaft 14, a longitudinal leather strip 12 spirally wrapped around the lining 11, and two coiled wires 13 respectively fastening top and bottom ends of the strip 12 to the golf club shaft 14.
FIG. 3 shows a conventional golf club grip 2 disclosed in U.S. Pat. No. 6,386,989, which includes a winding strip 20 made of a synthetic leather, such as polyurethane, and an inner sleeve 21. The strip 20 is spirally wound around the inner sleeve 21 and is adhered thereto through a double-sided adhesive tape 22 which is attached to the inner surface of the strip 20. The two ends of the strip 20 are respectively secured to a lip 240 of a threaded head 24 provided at the lower end of the inner sleeve 21 and to the lower end of a cover 23 provided on top of the golf club shaft 14.
In order to reinforce the connection between the strip 12 and the golf club shaft 14 and the connection between the strip 20 and the inner sleeve 21, the natural fixative 10 and the double-sided adhesive tape 22 are respectively used in the above conventional golf club grips 1 and 2 to provide an adhesive effect. However, the strip 12 or 20 is easily unravelled from the golf club shaft 14 or the inner sleeve 21 after a period of use due to insufficient adhesiveness of the glue 10 or the double-sided adhesive tape 22. While the strip 12 or 20 spirally wound around the golf club shaft 14 or the inner sleeve 21 can improve the securing of the strip 12 or 20 to the golf club shaft 14 or the inner sleeve 21, the grip 1 or 2 suffers from the following drawbacks:
1. The operation of winding the strip 12 or 20 is difficult and requires a certain level of skill. Careful attention must be paid for conducting the winding operation. Otherwise, the strips 12, 20 can become loosened and clearances can be formed between adjacent turns of the strip 12 or 20.
2. Since the strip 12 or 20 is wound spirally, it can not provide a grip surface which is as smooth as that formed by a single-turn winding sheet wrapped around a golf club shaft. The grip surface resulting from the spirally winding strip 12 or 20 is unable to provide a good feel of comfort.
In view of the aforesaid drawbacks, the inventor of this application has developed a sleeve-on type grip 3, as shown in FIG. 6. The grip 3 is formed as a multi-layered structure which includes a base layer 30 made of a close-cell foam and an anti-slip face layer 31 attached to the base layer 30. The anti-slip face layer 31 is bonded to the base layer 30 by using a high adhesion strength cement 32 (such as a polychloroprene resin, an adhesive alloy, etc.). The base layer 30 is a molded tubular lining sleeve, whereas the anti-slip face layer 31 is formed by tailoring a sheeting material.
The grip 3 formed as such can alleviate the problems encountered by the conventional grips 1 and 2. However, as the base layer 30 is molded into a tubular lining sleeve and as the shrinkage of the lining sleeve of the base layer 30 varies due to the change in temperature, material, and other parameters of the processing steps, such as forming, mold releasing, drying, etc., the dimension of the base layer 30 tends to deviate from the predetermined dimension thereof. Such a dimensional deviation can produce a clearance between the top end of the anti-slip face layer 31 and a cap 33 formed on top of the base layer 30. This affects adversely the appearance and quality of the golf club grip 3.
In addition, although the face layer 31 can be bonded effectively to the base layer 30 because of the use of the high adhesion strength cement, e.g. a polychloroprene resin, the cement, after being hardened, tends to reduce the extensibility of the grip 3. Owing to the insufficient extensibility of the grip 3, when a golf club shaft 4 is inserted into the grip 3, the grip 3 tends to burst at its axial seam 35 due to the insertion of the golf club shaft 4 which forces the grip 3 to expand. Moreover, it is difficult to sleeve the grip 3 over the golf club shaft 4 because of the insufficient extensibility of the grip 3.